Zinc May Reduce Duration and Severity of Common Cold

WEDNESDAY, Feb. 16 (HealthDay News) -- Zinc taken within 24 hours of common cold symptoms reduces symptom duration and severity; and preventive zinc therapy in children reduces cold incidence, missing school, and antibiotic prescriptions, according to a review published online Feb. 16 in the Cochrane Database of Systematic Reviews.

Meenu Singh, M.D., and Rashmi R. Das, M.D., of the Post Graduate Institute of Medical Education and Research in Chandigarh, India, assessed the effect of zinc on common cold symptoms in healthy adults and children in high-income countries. Literature searches identified two types of trials: 13 placebo-controlled therapeutic trials where zinc was used for at least five days as a treatment for common colds, and two preventive trials where zinc was taken for at least five months prophylactically.

The investigators found that zinc intake was associated with a significant decrease in duration and severity of common cold symptoms. In therapeutic trials, there was a significant difference in the proportion of patients who were symptomatic after seven days of zinc treatment compared to placebo (odds ratio, 0.45 in zinc group). In the preventive trials, the incident rate ratio was lower for developing a cold, being prescribed antibiotics, and missing school in the zinc group. The zinc group had a higher rate of adverse events, including bad taste and nausea.

"Given that some formulations (especially lozenges) produced side effects and not all formulations may be effective, the use of zinc to treat common cold symptoms is presently advised with caution," the authors write.